M.G.
with that being said, that is not unusual to see that requirement. ASME has the same requirement for Sec I and B31.1 and B31.3 as of 2007. But we need more info. What are you working on and what is the code of construction? I ditto what Brent in asking, where does AWS fit into this? Typically you don't see AWS as a piping design code unless it is for coal handling piping that is gravity feed with no pressure or something like it.
Thanks
Jim
The key word in your original statement is "final" RT.
Common procedure is to RT before stress releiving to investigate for weld flaws prior to investing in heat treatment, and then final RT after heat treat to verify no cracking.
i.e - It sucks to spend time and money on stress releiving to find in your "final" RT that you have a weld defect requiring repair, which makes you have to start all over again.
Preliminary RT is not a code requirement, its more of a CYA investment.
Final RT can be a code requirement.
Tim
M.G
is there some reason you can't divulge the code of construction? Or let us know how AWS figures into this? As a company we build a lot of power plants. We typically use P22. P91 and P92 material. We might perform info shots prior to the required volumetric test required by code after PWHT but for the most part we perform volumetric testing after PWHT. We do not, as a rule, perform a volumetric test prior to and after PWHT. This is mainly due to us bidding work hard money and figuring our NDE budget on code requirements, not above and beyond code requirements.
Thanks
Jim
This requirement is generally applicable to those alloys subject to stress relief cracking, predominantly the chrome molys. So you would not see it in D1.1.
Totally agree. Unless it is driven by product. Some Petro Chem work requires PWHT based on process. (what kind of process chemical is in the line) Just trying to figure out from the poster how AWS figures into his question and what is the code of construction.
Jim
I was just wondering why it's not address in the AWS Codes or Standards. It states that some material that is welded will have to wait 48 hours before it can be inspected because it can crack within that time period.
M.G.
Yes, and that is what your specification is calling for; NDT after the PWHT has been performed.
Al